The inverted microscope method of estimating algal numbers and the statistical basis of estimations by counting
TL;DR: If the organisms are randomly distributed, a single count is sufficient to obtain an estimate of their abundance and confidence limits for this estimate, even if pipetting, dilution or concentration are involved.
Abstract: Various methods for the estimation of populations of algae and other small freshwater organisms are described. A method of counting is described in detail. It is basically that of Utermohl and uses an inverted microscope. If the organisms are randomly distributed, a single count is sufficient to obtain an estimate of their abundance and confidence limits for this estimate, even if pipetting, dilution or concentration are involved. The errors in the actual counting and in converting colony counts to cell numbers are considered and found to be small relative to the random sampling error. Data are also given for a variant of Utermohl's method using a normal microscope and for a method of using a haemocytometer for the larger plankton algae.
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11 Feb 1999
TL;DR: The state of knowledge regarding the principal considerations in the design of programmes and studies for monitoring water resources and supplies and describes the approaches and procedures used as mentioned in this paper, and the information needed for protecting drinking water sources and recreational water bodies from the health hazards caused by cyanobacteria and their toxins.
Abstract: This book describes the present state of knowledge regarding the impact of cyanobacteria on health through the use of water. It considers aspects of risk management and details the information needed for protecting drinking water sources and recreational water bodies from the health hazards caused by cyanobacteria and their toxins. It also outlines the state of knowledge regarding the principal considerations in the design of programmes and studies for monitoring water resources and supplies and describes the approaches and procedures used.
The development of this publication was guided by the recommendations of several expert meetings concerning drinking water (Geneva, December 1995; Bad Elster, June
1996) and recreational water (Bad Elster, June 1996; St Helier, May 1997). An expert meeting in Bad Elster, April 1997, critically reviewed the literature concerning the toxicity of cyanotoxins and developed the scope and content of this book. A draft manuscript was reviewed at an editorial meeting in November 1997, and a further draft was
reviewed by the working group responsible for updating the Guidelines for Drinkingwater Quality in March 1998.
3,131 citations
Book•
29 May 2006TL;DR: Reynolds as discussed by the authors provides basic information on composition, morphology and physiology of the main phyletic groups represented in marine and freshwater systems and reviews recent advances in community ecology, developing an appreciation of assembly processes, co-existence and competition, disturbance and diversity.
Abstract: Communities of microscopic plant life, or phytoplankton, dominate the Earth's aquatic ecosystems. This important new book by Colin Reynolds covers the adaptations, physiology and population dynamics of phytoplankton communities in lakes and rivers and oceans. It provides basic information on composition, morphology and physiology of the main phyletic groups represented in marine and freshwater systems and in addition reviews recent advances in community ecology, developing an appreciation of assembly processes, co-existence and competition, disturbance and diversity. Although focussed on one group of organisms, the book develops many concepts relevant to ecology in the broadest sense, and as such will appeal to graduate students and researchers in ecology, limnology and oceanography.
1,856 citations
TL;DR: An examination of field data from representative lakes around the world indicated that direct temperature effects were secondary to indirect temperature effects (mixing) and nutrients in determining the dominance of bloom‐forming cyanobacteria in lakes.
Abstract: The literature was reviewed to determine the direct temperature effects on photosynthetic capacity (Pmax), specific respiration rate (Rest), and growth rate of bloom‐forming cyanobacteria (Anabaena, Aphanizomenon, Microcystis, Oscillatoria) and to assess the importance of direct tern‐perature effects on cyanobacterial dominance in lakes. This analysis is supported by field studies of Microcystis aeruginosa in a hypertrophic lake. The literature and field data show that Pmax, Rest, and growth rate are temperature‐dependent with optima usually at 25 °C or greater. The four genera varied in their response to low temperatures with Microcystis being most severely limited belw about 15 °C. Oscillatoria tended to tolerate the widest range of temperatures. However, an examination of field data from representative lakes around the world indicated that direct temperature effects were secondary to indirect temperature effects (mixing) and nutrients in determining the dominance of bloom‐forming cyanobacteria...
629 citations
01 Jan 2006
543 citations
Cites methods from "The inverted microscope method of e..."
...This method, now called the Utermöhl method (Utermöhl 1958), completed by Lund et al. (1958) with statistical basics of the precision of the counting method, has become the standard method for quantitative phytoplankton studies in both marine and freshwater environments....
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01 Jan 1925
TL;DR: The prime object of as discussed by the authors is to put into the hands of research workers, and especially of biologists, the means of applying statistical tests accurately to numerical data accumulated in their own laboratories or available in the literature.
Abstract: The prime object of this book is to put into the hands of research workers, and especially of biologists, the means of applying statistical tests accurately to numerical data accumulated in their own laboratories or available in the literature.
11,308 citations
212 citations
TL;DR: I n t r o d u c t i t i o n .
Abstract: I n t r o d u c t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489 Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 Physical Environment and Energy Supply . . . . . . . . . . . . . . . . . . . . . . . . . . 493 Tempel\"ature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494 Chemical Environment and Nutrient Supply . . . . . . . . . . . . . . . . . . . . . . . . 500 Photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504 Quantitative Estimation of Plant Material . . . . . . . . . . . . . . . . . . . . . . . . . . 508 Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508 Cell Constituents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 Carbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 Silicon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510 Nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 Chlorophyll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 Optical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 Other Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520 Interrelation of Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 Estimation of Growth in Natural Populations . . . . . . . . . . . . . . . . . . . . . . 522 Use of Experimental, Including Cultured, Populations . . . . . . . . . . . . . . 525 Mathematical Models of Population Behaviour . . . . . . . . . . . . . . . . . . . . . 531 Samples and Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 Plankton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 Benthos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539 Treatment of Collected Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 General Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 Plankton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 Benthos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547 Postscript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548
164 citations
TL;DR: The method here described has been applied to diverse algae and comparea with the Uterm6hl technique, and the results are given in comparison with other methods.
Abstract: The counting of algae by the method devised by Uterm6hl has many advantages over others. The present method which is based on it, is not suggested as an alternative if an inverted microscope is available. It needs only a small amount of easily constructed apparatus and, provided an ordinary microscope is available, can be carried out without much expense and in the absence of laboratory facilities~ for example in the home or on expeditions. Other methods that were devised suffered from the defect that it is very difficult to remove cells sedimented into narrow spaces such as narrow centiifage tubes or capillary tubes or pipettes. Though results could be obtained by using these alternative methods, which give a randomly distributed series of counts, the means, and often the range as well, were slightly but significantly lower than those obtained by the use of the Uterm6hl technique. To ensure that no loss of cells could occur when using the Uterm6hl technique, the volumes employed were such that the only sampling operation was pipetting from the water sample collected in the field to the counting chamber. In this way, possible losses due to pre-concentration or dilution of the water removed from the field sample was avoided. In any case, however, such losses should not occur if the treatment of a sample after collection is carried out properly, since it is itself equivalent to taking a sample, 'a process which can be repeated indefinitely without adding to the variability of the resulting count' (Ricker 1937, p. 78; see also Lund, Le Cren and Kipling, in prep.). The method here described has been applied to diverse algae and comparea with the Uterm6hl technique. The results are given in
33 citations